ML20203C393
| ML20203C393 | |
| Person / Time | |
|---|---|
| Site: | 05200003 |
| Issue date: | 12/08/1997 |
| From: | Quay T NRC (Affiliation Not Assigned) |
| To: | Liparulo N WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| References | |
| NUDOCS 9712150295 | |
| Download: ML20203C393 (4) | |
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Y Deceraber 8,1997 i
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Mr. Nicholas J. Liparulo, Manager Nuclear Safety and Regulatory Analysis Nuclear and Advanced Technology Division Westinghouse Electric Corporation P.O. Box 355 Pittsburgh, PA 15230
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION (RAI) ASSOCIATED WITH THE REVIEW OF THE AP600 HYDRO-DYNAMIC LOADS ON THE IN-CONTAINMENT REFUELING WATER STORAGE TANK (IRWST)
Dear Mr. Uparulo:
The Containment Systems and Severe Accident Branch has requested additionalinformation to complete its input for AP600 SER Section 6.2.8 related to the hydro-dynamic loads experienced by the IRWST as a result of ADS 1,2, and 3 discharge. The RAls are attached as an enclosure to this letter, if you have any questions regarding this matter, you may contact me at (301) 415-1118.
Sincerely, original signed by: Jerry N. 1)ilson Theodore R. Quay, Director Standardization Project Directorate Division of Reactor Program Management Office of Nuclear Reactor Regulation Docket No.52-003
Enclosure:
As stated
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i DOCUMENT NAME: A: HYDRO-ID.RAI To receive a copy of this document, Indicate !n the box: "C" = Copy without attachment / enclosure "E" = Copy with attachment / enclosure "N" = No copy OFFICE PM:PDST:DRPM l D.DSSA y p[
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Mr. Nicholas J. Liparuto Docket No.52-003 Westinghouse Electric Corporation AP600 cc:
Mr. B. A. McIntyre Mr. Russ Bell Advanced Plant Safety & Licensing Senior Project M. nager, Programs Westinghouse Electric Corporation Nuclear Energy Institute Energy Systems Business Unit 1776 i Street, NW P.O. Box 355 Suite 300 Pittsburgh, PA 15230 Washington, DC 20006-3706 Ms. Cindy L. Haag Ms. Lynn Connor Advanced Plant Safety & Licensing Doc-Search Associates Westinghouse Electric Corporation Post Office Box 34 Energy Systems Business Unit Cabin John, MD 20818 Box 355 Pittsburgh, PA 15230 Dr. Craig D. Sawyer, Manager Advanced Reactor Programs Mr. Sterling Franks GE Nuclear Energy U.S. Depanment of Energy 175 Curtner Avenue, MC-754 NE 50 San Jose, CA 95125 19901 Germantown Road Germantown, MD 20874 Mr. Robert H. Buchholz GE Nuclear Energy Mr. Frank A. Ross 175 Curtner Avenue, MC-781 U.S. Department of Energy, NE-42 San Jose, CA 95125 Office of LWR Safety and Technology 19901 Germantown Road Barton Z. Cowan, Esq.
Germantown, MD 20874 Eckert Seamans Cherin & Mellott 600 Grant Street 42nc Floor Mr. Charles Thompson, Nuclear Engineer Pinburgh, PA 15219 AP600 Certificatian NE 50 Mr. Ed Rodwell, Manager 13901 Gerrnantown Road PWR Design Certification Germantown, MD 20874 Electric Power Research Institute 3412 Hillview Avenue Palo Alto, CA 94303
3 REQUEST FOR ADDITIONAL INFORMATION ON THE AP600 IRWST HYDRO-DYNAMIC LOADS 480.1104 The following RAls have been generated based on the assumption that the hydro-dynamic loading in the IRWST is significant to the structures and piping. If this is not true, describe how the loading was considered.
480.1105 No information can be found on the drag induced forces acting on structure or piping submerged in the IRWST. Since the AP600 has submerged piping within the IRWST, the drag forces acting on those structures would need to be addressed. Those forces would include both the standard drag load associated with a structure within a constant velocity fluid field and the acceleration drag load from forces associated with fluid acceleration.
Please provide the methodology used to calculate the drag force on submerged piping and structural columns within the IRWST. Also, include the results of the analyses.
480.1106 WCAP-13891,"AP600 Automatic Depressurization System Phase A Test Data Report,"
does not discuss the fluid structure interaction (FSI) effects at the tank walls. The issue is how the stiffness of the test facility tank versus the stiffness of the IRWST tank floor and walls affects the measured loads. If the IRWST wall is excited, the wall may transmit forces to other attached structures and piping. Please describe how the FSIis considered for the specific AP600 plant IRWST, how the test facility analysis considers FSI, and what were the calculated loads whic6. will be imparted to the IRWST attached piping and structures.
480.1107 (a)
In WCAP-i3891,"AP600 Automatic Depressurization System Phase A Test Data Report,"
a floor pressure plot for test A-11, PE-10, page 380, shows a pronounced pressure oscillation beginning approximately 22.70 seconds and decaying quickly to zero by 22.80 seconds. This oscillation appears to be significantly la.vger, in terms of measured wall pressure, than any of the other tests conducted as shown in WCAP-13891, Table 1 " Test Matrix." Please explain the reason for this oscillation occuring at approximately 22.7 seconds and why the magnitude of this rapidly decayin0 pulse does not appear on other pressure plots. Also, provide the structural significanco of this load on the walls of the AP600.
(b)
In WCAP-13891,"AP600 Automatic Depressurization System Phase A Test Data Report,"
a floor pressure plot for test A-18, PE-10, page 464, does not show the same spike at 22.7 seconds but a much lower and earlier p :x occurring at approximately 5 seconds.
This would appear to be within the air clearing phase of the quencher phase followed by somewhat steady steam condensation out to 50 seconds. The expanded time scale plot on page 465 of WCAP-13891 provides added insightinto the pealcs occurring at approxi-mately 5.0 seconds which shows irregular oscillations shifted to the positive pressure and appear to be characteristic of an oscillating air bubble. The negative portion of the curve appears jagged, irregular and uncharacteristic of e.n air bubble rising to the surface.
Please explain what phase the quencher is operating in (i.e. air clearing or unsteady steam condensation) and the apparent difference with essentially the same test conditions except for nominal temperature as test A11 as shown in WCAP 13891, Table i " Test Mctrix."
Enclosure
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2-480.1108 The IRWST attached piping and submerged structures such as the support columns,
' Integrated HD Support" as shown on drawing 1030 P2 001, revision 7 could experience an acceleration and or drag force from the IRWST tank during a quencher discharge.
Please provide a discussion on the magnitude for those accelerations and forces and explain how thoso accelerations and forces were developed.
480.1109 There was a minimal amount of instrumentation (1 e. 8 pressure transducers) within the IRWST for the ADS tests. Discuss how this level of instrumentation can measure the various loads with a degree of precision that is necessary.
480.1110 Based on the measured test forces, how were the AP600 design loads determined and with what level of margin.
480.1111 Show how the ADS test conditions (pool temperature, pool submergence, and pipe flow in Table 1, page 15 of WCAP-13891) envelopes the DBA design conditions.
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